1. Field of the Invention
The present invention is related to the suction box which dehydrates when building board such as inorganic board is molded and dehydrator with pressurization and forming machine using thereof.
2. Description of the Related Art
The following description sets forth the inventor's knowledge of related art and problems therein and should not be construed as an admission of knowledge in the prior art.
Conventionally, in house, inorganic building board can be used as external wall material, roofing material, external element material or interior wall material. And manufacturing process as referred to as wet process is overused when inorganic building board is produced. In this wet process, water is added in raw material for building boards abundantly, and raw material becomes liquid slurry. And material slurry flows down on water permeability sheet such as felts, and forming molds intermediate of a building board. A suction box is placed under water permeability sheet such as the felts which is flowed down material slurry, extra water is dehydrated through the sheet by aspiration. In addition, it drains the unnecessary water to a suction box that there is in intermediate of inorganic building board by keep pressurizing with the use of dehydrator with pressurization having a suction box. By this, content of water in intermediate of a building board is decreased, and it is molded in the shape of a plate, and it makes cure, and inorganic building board is produced afterwards.
For example, for suction box used conventionally, there is suction box 9 shown in FIGS. 16 and 17. Steel perforated panel 93 is arranged to this suction box 9, wherein steel perforated panel 93 is made from lot of water drip holes 931, wherein lot of water drip holes 931 are formed on plural elongated protruding portions 923, wherein plural elongated protruding portions 923 are formed to bottom plate portion 921 in frame member with bottom plate 92. And intermediate of building board 8 containing water 81 is put on suction box 9, and this intermediate of building board 8 is kept pressurizing by a pair of presses 96, and vacuum aspiration does suction box 9 with an aspirator. Then, Water 81 included in intermediate of building board 8 goes along lot of water drip holes 931 of steel perforated panel 93, and it flows down to suction box 9. In suction box 9, the water which flowed down goes along passage 924 formed in an interval between plural elongated protruding portions 923, and it is drained of water by external of suction box 9.
As thus described, for suction box 9 dehydrating water 81 by lot of water drip holes 931, there is manufacturing apparatus of cement mortal molded product disclosed by Japanese utility model No. 2,555,851. In this manufacturing apparatus, drip steel plate (steel perforated panel 93) includes a lot of vacuum holes for dehydration (water drip holes 931). Here, opening area per unit area by vacuum hole for dehydration in peripheral portion is larger than thereof of center portion. By this, cement mortal molded product placed in a peripheral portion of drip steel plate by facing is aspirated chiefly, and cement mortal molded product superior in a good appearance and physical property is produced.
In addition, in Japanese patent No. 3,482,879, the suction box which plural plates are aligned every uniformity, and formed dehydration hole of a slit between plates next to each other is disclosed. In this suction box, each plates are fitted as against plural rails installed in the upper surface releasably. By this, a replacement of each plates becomes simple and easy, and hour to need for maintenance is shortened.
However, in the conventional suction box, there are the following problems.
When intermediate of building board is dehydrated by suction box of Japanese utility model No. 2,555,851 or Japanese patent No. 3,482,879, there is the case that lot of water drip holes 931 (vacuum hole for dehydration) in steel perforated panel 93 (drip steel plate) make clogging by one part of materials of intermediate of building board. Therefore it is necessary to clean regularly to cancel clogging.
In addition, in Japanese patent No. 3,482,879, it is difficult to adjust opening area ratio of dehydration space of a slit formed between plates. In other words the installation number of plate cannot be changed so that installation position of plural rails is fixed in Japanese patent No. 3,482,879. Therefore, for change of opening area ratio of dehydration space, it can deal only by changing thickness of plate.
The description herein of advantages and disadvantages of various features, embodiments, methods, and apparatus disclosed in other publications is in no way intended to limit the present invention.
For example, certain features of the preferred embodiments of the invention may be capable of overcoming certain disadvantages and/or providing certain advantages, such as, e.g., disadvantages and/or advantages discussed herein, while retaining some or all of the features, embodiments, methods, and apparatus disclosed therein.